How does a copper jacketed lead bullet "get the roughness out" of a steel bore?
Really? Well, since a copper jacket can't do anything to a steel bore, I guess barrels just never wear out, right?
Just got a new Noveske rifle. They're widely considered one of the elite barrel makers for the AR-15. Their included documentation said to clean the barrel then go shoot it, no special break-in technique required.
This is apples and oranges. The Pac Nor barrels that Noveske uses are chrome lined (as are most AR-15 barrels). If you have one of the stainless models, those barrels are hand lapped, unless I'm mistaken. Either way, no breaking in is necessary.
Ya know what? I'm just shy of 70 years old and I've been a shooter since I was about 6 years old and my Dad (a USMC ordnance officer at the time) started teaching me.
No disrespect to you or your dad, but we aren't talking about military rifles here. We're talking about a hunting rifle and I'm assuming that the utmost in accuracy is a concern.
I'd imagine that for most, breaking in a barrel may seem like it does nothing because they never realize the benefits of it.
Properly breaking in a barrel can and often does make a difference between having a barrel that needs to be de-coppered every 30 rounds and a barrel that can go several hundred rounds without any significant copper fouling.
Call it a myth if you want, but I've seen rifles go from averaging .5 MOA groups to MOA groups just because the throat is fouled.
Of course, if all you need is the rifle to just shoot good enough, then don't worry about it. If you want to get the utmost in accuracy out of your rifle, I'd suggest that you break the barrel in.
Take what I say with a grain of salt, though. I don't shoot any over the counter rifles for target shooting and the level of accuracy that I expect may not be what you expect.